AAVSO report shows unusual comparison star magnitudes
Stacking program, astrometric (plate) solver, fits file viewer
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that wispy pattern is a fault in my flat, it has nothing to do with ASTAP
Tonight I obtained a complete new set of images (light/darks/flats/dakflats) and tried a calibration. I can run calibration without problems only if software and files reside on the same drive. If they are located on different hds calibration fails.
Running calibration with the same files already converted to fits works if software and data are on two different drives. The resulting cal.fits file however displays a check pattern.
Is your drive a network drive? Here is I split the files to a harddisk and memory stick they are all accessed without problems.
That you see a checker pattern should be normal but your image looks a little weird since only 1/4 of the pixels (red or blue) is different. For green extraction this should be no problem. The images you shared doesn't show any signal drop of at the out areas so that is good.
The photometry results are somewhat curious. The graph shows five outliers at mag 13 which are listed in the report file with different magnitudes (one even at mag 15) and again different in the report form. In the report form there are no magnitudes for the observations prior to the outliers (marked in screenshot). The corresponding images look ok visually.
Looks like the measurements which are blank are getting a random magnitude value. That is not good. I will look if I can reproduce it.
I assume the problem is gone in the latest development version since I can not reproduce it. Can you try this version dated 2025.06.30?:
http://www.hnsky.org/astap_setup.exe
Not sure what happened: my last posts simply disappeared :-(
Solved the problem: it is obviously related to an access problem with one of my HDs - astap seems not to be able to write on this drive. I checked all the permissions but I don't see a problem. On other drives the problem does not exist.
I obtained a new series the night before. In general the results look good but there are a number of unrealistic 13 mag outliers in the graph which are not shown in the report table - instead the preceding mag value is always blank. The AAVSO report file also contains some 13 mag and even a 15 mag outlier which is not shown in the graph (attachments). Could you please take a look?
cs Axel
I just finished ASTAP 2025.07.02, I will have a look tomorrow morning. Can you share a few image files around the time the abnormal value occurs? Then I can reproduce the effect here and trace the cause using the debugger.
Han
I'll send the images tomorrow.
There was a major bug in the last version. The variables magnitudes where not reported. I fixed it today.
I haven't seen a link to your images. I tried to simulate your problem but could not recreate it here. I will need your images to trace the problem.
Han
Sorry for the delay - too much work.
I ran the images again with ASTAP 2025.07.02 and the outliers disappeared. So that problem seems solved.
When opening the report form the comparison star list remained empty (online DB mag 15 option) even though a single check star was show in the check star list. When trying to report to file the check star list went red and no file was exported (see attachment).
Could you please explain the meaning of the changed entries in AAVSO annotation list box? I regret the P< 3 option appears to have been dropped - for variable star observations of short period variables that has been very helpful to avoid overloading the image annotations with long period variables. The most convenient option would of course be the possibility to specify a period range in a separate list but I guess that is too much work.
cs Axel
Hi Axel,
Version 2025.07.02 is a bad one. The variable magnitude is missing in the report. Download version 2025.07.04 or 2025.07.05 development version.
I noted that AAVSO VSX database is filled with variables from Gaia. Many have never been observed by AAVSO members and they do not have an AUID. So you can not report them unless you request an AUID number first. So I decided to replace the filtering by an other one filtering which just checks if the variable has an AUID number. I assume this will work for you as well to filter out many variables. But please test it. If it is not wroking for you tell me. See attached screenshot.
Do not select " Online magn 15 (std field) . This is a special database for finding your system transformation coefficients by imaging a cluster like M67. Try latest ASTAP version. If still no success attached the image involved so I can have a look.
Cheers, Han
I
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Hi Han,
I used version 2025.07.04:
measure all Online DB mag 15: photometry appears to work fine but comp star list is empty, check star is automatically set and report does not work
Manual star selection: just have a look at the attachment
cs Axel
The question marks ??????. I suppose the first image is not solved???
The comps star combobox is only filled if you have clicked on stars green annotated starting with 000-.... annotion like attached screenshot.
If this not helps, send me just one image so I can have a look.
Han
Hi Han,
I checked: the first image is solved. I reran a manual star selection with two green stars in the vicinity. Please see attachments for the field and the result. I have added the first image of the series. If you need any further images please let me know.
cs Axel
seems I can not select attachments from different directories in one post so here the screenshots
It works here. See attached. The weird thing is that the stars are in the variable combobox. They somehow lost the 000- of the abbreviations. So 000-BNL-800 is displayed as BNL-800. Weird, I will have a look into the code.
I can not explain it.
Which "AAVSO annotation" is selected in the photometry tab?
Can you download a fresh copy of the variabel star database and install it:
https://sourceforge.net/projects/astap-program/files/star_databases/variable_star_database.exe/download
If that doesn't help, Can you delete the ASTAP configuration and start again. See this menu:
I will continue tomorrow.
online DB mag 15
I'll try your suggestions and report back. Till tomorrow!
cs Axel
The week was too busy for astronomy... I installed a new copy of the variable star database and deleted the configuration. Still no success: the report form first remains empty (astap.jpg) and after selecting the variable comparison and check star lists remain empty (astap2.jpg)
I'm still baffled why this happens. Can we set up a zoom or other video connection so I can see how it happens? I will send you by a personal mail my email adress and phone number for a whatsapp or Signal communication.
This problem should be fix. For the mometn can you check version again in the ASTAP about menu.
Han
Let me first again run the complete sequence from the RAW files onwards. I will also check for differences between my installation on PC and laptop. On laptop I am running 15.07.08 (64bit).
For my last runs I loaded only the NEF_cal_TG.fit files in the photometry tab. Is that ok?
cs Axel
Yes should be fine. Any file will do.
Try mode "Measure all annoted, SNR>30" in tab photomtry and just press play button.
Cheers, Han
Just completed a complete analysis beginning with the raw files, software and data both on an external ssd.
astap.jpg shows report form after 'Measure all annoted, SNR>30' run, astap2.jpg after selecting the variable and astap3.jpg same after 'Measure all annoted, SNR>10'. The photometry looks ok, but comparison/check star lists always remain empty.
I should have deleted the last 7 images where trees begin to intrude but that wouldn't change the results I guess.
cs Axel